US 11,883,912 B2
Welding power supply device
Chikanori Takami, Osaka (JP); Hikaru Mizushima, Osaka (JP); and Ichiro Umezawa, Osaka (JP)
Assigned to DAIHEN CORPORATION, Osaka (JP)
Appl. No. 16/605,303
Filed by DAIHEN CORPORATION, Osaka (JP)
PCT Filed Apr. 4, 2018, PCT No. PCT/JP2018/014407
§ 371(c)(1), (2) Date Oct. 15, 2019,
PCT Pub. No. WO2018/193843, PCT Pub. Date Oct. 25, 2018.
Claims priority of application No. 2017-084593 (JP), filed on Apr. 21, 2017.
Prior Publication US 2020/0122266 A1, Apr. 23, 2020
Int. Cl. B23K 9/10 (2006.01); B23K 9/073 (2006.01); H02M 3/155 (2006.01); H02M 7/48 (2007.01)
CPC B23K 9/1043 (2013.01) [B23K 9/073 (2013.01); H02M 3/155 (2013.01); H02M 7/48 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A welding power supply device comprising:
an inverter circuit that converts DC power into AC power and outputs the AC power to a welding load; and
a voltage superimposing circuit that superimposes a restriking voltage on an output to the welding load when a polarity of an output current of the inverter circuit switches,
wherein the voltage superimposing circuit includes:
a restriking capacitor to be charged with the restriking voltage;
a charging circuit that charges the restriking capacitor with the restriking voltage; and
a discharging circuit that discharges the restriking voltage charged in the restriking capacitor,
wherein the charging circuit includes:
a DC power supply that outputs DC voltage;
a voltage booster that boosts the DC voltage of the DC power supply; and
a current sensor that is arranged between the DC power supply and the restriking capacitor and inside the charging circuit and that detects a current inputted to the charging circuit,
wherein the charging circuit charges the restriking capacitor in both a first state and a second state following the first state during a period of time between an occurrence of discharging the restriking voltage and a next occurrence of discharging the restriking voltage, the first state being a state in which the DC voltage of the DC power supply is directly applied to the restriking capacitor, the second state being a state in which the DC voltage boosted by the voltage booster is applied to the re-striking capacitor, and
wherein the charging circuit switches from the first state tothe second state when a value of the current detected by the current sensor decreases down to a predetermined current value for a first time after a most recent one of at least one event that a value of the output current of the inverter circuit changes to its minimum or maximum value occurs.